<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <form action="">
        邮箱：<input type="email">
        <input type="submit" value="提交">
        <input type="tel">
        <input type="submit" value="提交">
        <input required="required" placeholder="请输入用户名">
        <input autofocus="autofocus">
        <input autocomplete="off" name="username">
        <input type="file" multiple="multiple">
        <input type="submit" value="提交">
    </form>

</body>

</html>